docs: def send(self, obj):
          """
          Send an object to the remote server; block and return the reply
          if the socket type is REQ.
  
          :param obj:
              the Python object to send
          """
          self.zsocket.send_pyobj(obj)
          self.num_sent += 1
          if self.socket_type == zmq.REQ:
              return self.zsocket.recv_pyobj()